Using an imaging device to correct positioning errors

Abstract

A control device controls a control target apparatus including a moving part and an imaging device. The moving part is configured to change its position relative to a target as the moving part moves, and the imaging device is configured to acquire captured image of the target. Additionally, the control device includes a drive unit that drives the moving part, based on a drive command signal to move the moving part to a target position. Further, the control device includes a relative position estimation unit that calculates an estimated value of a relative position between the target and the imaging device, based on the drive command signal. Additionally, the control device includes a template image correction unit that corrects a preregistered template image, based on a time-series signal of the estimated value of the relative position within an imaging time of the imaging device, and a target position correction unit that corrects the target position using the corrected template image.

The invention claimed is: 
     
       1. A control device to control a control target apparatus including a mounting head and an imaging device to change a position relative to a target as the mounting head moves and acquire a captured image of the target, the control device comprising:
 drive circuitry to drive the mounting head, based on a drive command signal to move the mounting head to a target position; and 
 processing circuitry configured to: 
 calculate an estimated value of a relative position between the target and the imaging device, based on the drive command signal, 
 correct a preregistered template image, based on a time-series signal of the estimated value of the relative position within an imaging time of the imaging device resulting in a corrected template image, 
 correct the target position using the corrected template image, 
 calculate the corrected template image in a spatial frequency domain by performing an operation to apply a filter to the corrected template image in the spatial frequency domain, 
 the control device further comprising:
 an image processor to output an observed value of the relative position by image processing based on the captured image and the corrected template image in the spatial frequency domain, and correct the target position, based on the estimated value and the observed value. 
 
 
     
     
       2. The control device according to  claim 1 , wherein the processing circuitry is further configured to:
 simulate blurring of the captured image based on the time-series signal to generate a simulation result, and 
 correct the template image based on the simulation result. 
 
     
     
       3. The control device according to  claim 1 , wherein the processing circuitry is further configured to:
 calculate, based on the time-series signal, the filter corresponding to blurring of the captured image caused by a change in the relative position during imaging of the imaging device. 
 
     
     
       4. The control device according to  claim 1 , further comprising:
 the processing circuitry is further configured to correct the target position, based on the estimated value and the observed value of the relative position. 
 
     
     
       5. The control device according to  claim 4 , wherein the image processor outputs the observed value using template matching. 
     
     
       6. The control device according to  claim 1 , wherein the processing circuitry is further configured to:
 calculate a drive command signal including a current feedforward signal, in which gain of a frequency component exciting mechanical vibration of the control target apparatus is reduced, and a position reference signal that the mounting head needs to follow, based on a transfer function indicating mechanical characteristics of the control target apparatus, and input the drive command signal to the drive circuitry, calculate, based on the transfer function, the estimated value of the relative position when the drive circuitry performs two-degree-of-freedom control using the current feedforward signal and the position reference signal. 
 
     
     
       7. A control method for a control device to control a control target apparatus including a mounting head and an imaging device to change a position relative to a target as the mounting head moves and acquire a captured image of the target, the method comprising:
 calculating an estimated value of a relative position between the target and the imaging device, based on a drive command signal input to drive circuitry to drive the mounting head; 
 correcting a preregistered template image, based on a time-series signal of the estimated value of the relative position within an imaging time of the imaging device resulting in a corrected template image; 
 correcting the target position to which the mounting head is to be moved using the corrected template image; 
 calculating the corrected template image in a spatial frequency domain by performing an operation to apply a filter to the corrected template image in the spatial frequency domain; 
 outputting an observed value of the relative position by image processing based on the captured image and the corrected template image in the spatial frequency domain; and 
 correcting the target position, based on the estimated value and the observed value.